Piston



Patented Dec. 8, 1925.

NEWTONJ. BUREN, F TACOMA, WASHINGTON.

PISTON.

, Application filed September 22, 1925. Serial No. 57.872.

' To all whom it may concern:

Be itknown that I, NEWTON J. BUREN, a citizen of the United States of America, residing at Tacoma, in the county of Pierce and State of Washington, have invented certain new and useful Improvements in Pistons, of which the following is a specification. I k This invention relates to new and useful improvements in pistons.

The primary object of the invention is to enable an aluminum alloy to be used in form 1 ing a solid skirt piston, having a clearance of one-thousandth or less per inch of piston diameter, without resorting to slots in the skirt or to splitting the skirt in any manner.

A further object of the invention is to provide, in a piston having a solid skirt and relief areas at't-he wrist pin hole sides of the skirt, means for alining the assembled piston, wrist pin, and connecting rod.

Other objects and advanta'es of the invention will be apparentof the following description.

In the accompanying drawing forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

Figure l is a side elevational view of a" piston provided with-the features of construction embodying this invention,

Figure 2 is a bottom plan view of the piston shown. in Fig. 1,

Figure 3 is a side elevational view of the piston taken at right angles to the view illustrated in Fig. 1,'and

Figure 4 is afragmentary sectional view taken upon line IVIV of Fig. 1.

In the drawing wherein for the purpose of illustration is shown a preferred embodiment of this invention, the numeral 5 designates the body portion of the piston which specificallyincludes the ring grooves 6 of ordinary construction and the oil checks,

where the piston is to be bled for oil, at the head portion thereof. The skirt portion 8 is provided'with suitable "wrist pin holes 9 and relief areas 10 extending from points immediately below the oil check 7 to the bottom edge 11 of the skirt and on thesame during the course sides of the skirt portion as the sides thru which the wrist pin holes 9 enter the same.

Juxtaposed to the oil check 7 is a top land 12 which is turned to a diameter ten thousandths, or more, under the size of the cylinder into which the piston 'is fitted. The

skirt portion 8, below the wrist pin holes 9, is provided with a bottom land 13 which is turned to the same diameter as the land 12 and may be located as far down the skirt as possible, or desirable, without this lower and going out of the cylinder when the pis ton is at the extreme inner end of its strokes It will be seen, by inspecting the various figures, that the portions 8 of the skirt 8 constitutes the total wearing surface of the piston as no wearing surface is provided in any portion of the relief areas 10. The relief areas, in extending clear to the bottom edge of the skirt, provide for the expansion of the piston so that no portion of the latter within the relief area will come in contact with the cylinder wall and so that an aluminum alloy may be used in forming a piston skirt withoutslots or splits.

It will be very apparentthat a straight edge or an alining 11g, such as is used in shops to aline pistons and connecting rods,

may beplaced against the lands 12 and 13 for alining the piston and connecting rod.

The lands12-and 13, by being turned to a diamcter,'can be calibrated with a micrometer to test theroundness of the piston. This feature of testing the roundness of a piston is not possible where the piston is reieved clear to the bottom edge of the skirt, as there is no surface upon which to place the micrometers.

It is to be understood that the form of this invention herewith shown and described is to betaken as a preferred example of the same, and that various changes in the shape, size, and arrangement of parts may be re sorted to without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described the invention, I claim 1. In a lief areas,

areas formedtruly cylindrical, of less diameter than the unrelieved portion of the skirt said circumferential areas being turned on and traversing said relief areas. the same diameter which is less than the 4 2. In apiston, an uninterrupted skirt pord ameter of the wearing surfaces of the 1 tion having diametrically opposed relief skirt. 5 areas extending to the bottom edge of the In testimony whereof I afiix my signature.

skirt, and circumferentially extending concentric areas traversing said relief areas, NEWTON J. BUREN. 

